The invention pertains to methods of forming metal-comprising materials within openings, and has particular utility for methods of forming metal-comprising materials within openings having aspect ratios of greater than or equal to about 6:1.
Continuing goals in semiconductor fabrication processes are to decrease the amount of semiconductor wafer real estate consumed by electrical components, and to decrease the amount of semiconductor wafer real estate consumed by electrical interconnects between components. A method of reducing real estate consumed by electrical components and interconnects is to form the components and interconnects within vertical openings having high aspect ratios. For purposes of interpreting this disclosure and the claims that follow, a high aspect ratio opening is defined as an opening having an aspect ratio of greater than or equal to about 6:1.
Electrical components and interconnects can comprise metal-comprising materials, such as, for example, aluminum, aluminum alloys, tungsten, or titanium. It is difficult to provide such metal-comprising materials uniformly within high aspect ratio openings. For instance, if it is attempted to deposit such metal-comprising materials into a high aspect ratio opening, the materials will frequently form a bridge over the opening, rather than filling the opening. Methods have been developed for pushing bridging material into an opening by applying a substantially static high pressure to the material to drive it into the opening. Such methods work acceptably for openings having aspect ratios of less than 6:1, but frequently will not adequately drive metal-comprising materials into openings having aspect ratios greater than or equal to 6:1. Accordingly, it is desired to develop alternative methods for providing metal-comprising materials within high aspect ratio openings.
In one aspect, the invention encompasses a method of providing a metal-comprising material in a high aspect ratio opening. A substrate having a high aspect ratio opening extending therein is provided. A metal-comprising layer is formed over the opening. A first pressure is provided against the metal-comprising layer. The pressure against the metal-comprising layer is ramped to a second pressure at a rate of from about 1 atmosphere per second to about 100 atmospheres per second to force the metal-comprising layer into the opening.
In another aspect, the invention encompasses a method of providing a metal-comprising material in a high aspect ratio opening. A substrate having a high aspect ratio opening extending therein is provided. The opening has a widest portion and a width at said widest portion. A metal is sputter-deposited in a first chamber to form a metal-comprising layer over the opening. The metal-comprising layer has a thickness that is at least about twice the width of the opening. The substrate is transferred to a second chamber having a first pressure therein. While the substrate is within the second chamber, the pressure within the second chamber is ramped at a rate of at least about 20 atmospheres per second to a second pressure to force the metal-comprising layer into the opening.